GB790355A - Compression refrigeration apparatus - Google Patents

Abstract

790,355. Refrigerating. SULZER FRERES SOC. ANON. Aug. 17, 1956, No. 25288/56. Class 29 [Also in Groups XXVI and XXXIV] Compression refrigeration apparatus comprises a compressor 2 and an expansion turbine for the refrigerant in which the shaft 27 of the turbine is supported on gas which is under pressure and is taken from the gas by which the turbine is operated. In the preferred embodiment air is compressed by compressor 2 and led through a water cooler 5 and heat exchanger 6 to the expansion turbine 7 where it is cooled and led to the cold room 10, although the turbine may be located in the coldroom, afterwards passing through heat exchanger 6 to a centrifugal compressor 15, mounted on the same shaft 27 as the turbine 7, and to the compressor 2. A line 17 by-passing the turbine leads compressed air to the bearings 25, 25<1> of shaft 27, which is of a heat insulating material preferably a thermoplastic, through a switch 19. From the bearings the air flows back into the circuit at a point before the centrifugal compressor 15. On starting compressed air is pumped through pipe 32 and switch 19 to the bearings until pressure in the system is at an adequate level. The shaft 27 is in three sections 51, 58, 52 as shown (Fig. 2) and the bearing 25 of section 51 carrying the blade wheel 35 of the expansion turbine is formed to take both axial and radial thrusts whereas the bearing 25<1> of section 52 carrying the compressor 43 is for radial thrust only. Compressed air enters at 50 and is directed by passages 49 into annuli 47, 48 surrounding bearings 25, 25<1> respectively. From annulus 47 air passes through passages 54 to recesses 53 and through passages 75 to annular chambers 74. Circular grooves 71 surround the shaft section 51 and are connected by longitudinal slots 55. After circulating about the bearing the air leaves by passages 56, 57 and 60. The bearing 25<1> is provided with the recesses 53 only. To ensure that warm compressed air does not enter the bearings the wheel 42 of the centrifugal compressor is provided with a serrated surface 46.